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1   /***
2    * Redistribution  and use  in source  and binary  forms, with  or without
3    * modification, are permitted provided  that the following conditions are
4    * met :
5    *
6    * . Redistributions  of  source  code  must  retain  the  above copyright
7    *   notice, this list of conditions and the following disclaimer.
8    *
9    * . Redistributions in  binary form  must reproduce  the above  copyright
10   *   notice, this list of conditions  and the following disclaimer in  the
11   *   documentation and/or other materials provided with the distribution.
12   *
13   * . The name of the author may not be used to endorse or promote products
14   *   derived from this software without specific prior written permission.
15   *
16   * THIS SOFTWARE IS  PROVIDED BY THE  AUTHOR ``AS IS''  AND ANY EXPRESS  OR
17   * IMPLIED  WARRANTIES,  INCLUDING,  BUT   NOT  LIMITED  TO,  THE   IMPLIED
18   * WARRANTIES OF MERCHANTABILITY AND  FITNESS FOR A PARTICULAR  PURPOSE ARE
19   * DISCLAIMED.  IN NO  EVENT SHALL  THE AUTHOR  BE LIABLE  FOR ANY  DIRECT,
20   * INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR  CONSEQUENTIAL  DAMAGES
21   * (INCLUDING,  BUT  NOT LIMITED  TO,  PROCUREMENT OF  SUBSTITUTE  GOODS OR
22   * SERVICES;  LOSS  OF USE,  DATA,  OR PROFITS;  OR  BUSINESS INTERRUPTION)
23   * HOWEVER CAUSED  AND ON  ANY THEORY  OF LIABILITY,  WHETHER IN  CONTRACT,
24   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25   * ANY  WAY  OUT OF  THE  USE OF  THIS  SOFTWARE, EVEN  IF  ADVISED OF  THE
26   * POSSIBILITY OF SUCH DAMAGE.
27   *
28   * $Id: Input.java,v 1.12 2005/09/10 11:26:47 mat007 Exp $
29   */
30  
31  package jtge.engine.io;
32  
33  import jtge.engine.command.ICommand;
34  import jtge.engine.handler.AbstractProducer;
35  import jtge.engine.handler.IConsumer;
36  
37  /***
38   * Handles the input logics.
39   * <p>
40   * This class acts as the abstraction in the bridge pattern.
41   *
42   * @author Mathieu Champlon
43   * @version $Revision: 1.12 $ $Date: 2005/09/10 11:26:47 $
44   */
45  public class Input extends AbstractProducer implements IInput
46  {
47      private final IDisconnectionObserver observer;
48      private final IInputImp input;
49  
50      /***
51       * Create an input.
52       *
53       * @param consumer the consumer to forward the read commands to
54       * @param observer the observer
55       * @param input the input implementation
56       */
57      public Input( final IConsumer consumer, final IDisconnectionObserver observer, final IInputImp input )
58      {
59          super( consumer );
60          if( observer == null )
61              throw new IllegalArgumentException( "argument 'observer' is null" );
62          if( input == null )
63              throw new IllegalArgumentException( "argument 'input' is null" );
64          this.observer = observer;
65          this.input = input;
66      }
67  
68      /***
69       * {@inheritDoc}
70       */
71      public final void read()
72      {
73          while( !isClosed() )
74          {
75              final ICommand command = input.read();
76              if( command != null )
77                  forward( command );
78              else if( isClosed() )
79                  observer.closed( this );
80              else
81                  throw new InputOutputException( "null command from input" );
82          }
83      }
84  
85      /***
86       * {@inheritDoc}
87       */
88      public final void close()
89      {
90          if( !isClosed() )
91          {
92              input.close();
93              observer.closed( this );
94          }
95      }
96  
97      /***
98       * {@inheritDoc}
99       */
100     public final boolean isClosed()
101     {
102         return input.isClosed();
103     }
104 }